I have a similar, not quite as good, pitcher (http://whatifsports.com/HBD/Pages/Popups/PlayerProfile.aspx?pid=3327428) set at 85/100 and he's been an All-Star 2 of his 3 full seasons, and he's on his way to his 3rd.

Stamina of 60+ dur of 30+ is enough to be a starter.

My pitching staff in Hamilton:

Matty Paniagua (R)		85 (100)	30	74	61	83	65	95	84	85	84	67	71	39	46	$378K
Julio Castillo (R)		70 (92)	22	77	57	95	69	83	76	57	70	75	57	53	44	$5.6M
Jalal Darling (R)		100	27	94	62	87	79	88	87	55	80	64	54	26	40	$7.8M
Ariel Olivares (R)		100	22	80	54	84	68	74	87	84	92	77	55	34	51	$1.3M
Deivi Chavez (L)		100	34	59	57	84	95	67	96	85	90	70	43	39	0	$378K

Darling adn Paniagua are set at 80-95.

I've used starters with ST as low as 48, with pitch counts around 65/75.  If you carry more than one starter like that you need a good bullpen, with several guys with high DUR.  To me, the best way to construct a pitching staff is to figure out about how many innings there are, plan for max innings you can get out your best guys, whatever their roles are (and they do not have to be traditional), and then build your staff around that.  But my teams have been somewhat unconventional at times.  (Like not using "Closers" if at all possible and using high DUR relievers in Tandem B roles).